On addition of aqueous NaOH to a salt solution, a white gelatinous precipitate is formed, which dissolves in excess of alkali. The salt solution contains

An inorganic compound (X) shows the following reactions : (a) It is white solid, exists as dimer and fumes in moist air. (b) It sublimes at 180^@ C and forms monomer on heating to 400^@ C . ( c) Its aqueous solution turns blue litmus red and gives a white precipitate with AgNO_(3) solution which is soluble in excess of NH_(4) OH . (d) Addition of NaOH to the solution of (A) gives a white gelatinous precipitate which is, however, soluble on excess of NaOH . Identify the compound (A) .

An inorganic compound (X) shows the following reactions : (a) It is white solid, exists as dimer and fumes in moist air. (b) It sublimes at 180^@ C and forms monomer on heating to 400^@ C . ( c) Its aqueous solution turns blue litmus red and gives a white precipitate with AgNO_(3) solution which is soluble in excess of NH_(4) OH . (d) Addition of NaOH to the solution of (A) gives a white gelatinous precipitate which is, however, soluble on excess of NaOH . Identify the compound (A) .

Questions carrying 2 marks : Addition of NaOH solution to a solution of Zn Cl_2 produces a white precipitate which dissolves in excess of NaOH and forms soluble sodium zincate. Why?

To which of the following metal salt solution when solution of caustic soda is added, a precipitate is obtained which dissolves on adding excess of caustic soda solution?

A colourless solution of a salt yields a white precipitate with dropwise addition of caustic alkali, which however. dissolves in excess of the alkali. The salt is a (a) zinc salt, (b) aluminium salt, (c) either a zinc salt or an aluminium salt, (d) none of (a) or (b).

A pale green crystalline metal salt of M dissolves freely in water. It gives a brown precipitate on addition of aqueous NaOH. The metal salt solution also gtives a black precipitate on bubbling H_2 S in aqueous medium. An aqueous solution of the metal salt decolourizes the pink colour of the premanganate solution. The metal in the metal salt solution is

A white substance (A) reacts with dilute H_(2)SO_(4) to produce a colourless suffocating gas (B) and a colourless solution (C )/ The reaction of gas (B) with potassium iodate and starch solution produce a blue colour solution. Aqueous Solution of (A) gives a white precipitate with BaCl_(2) solution which is soluble in dilute HCl . Addition of aqueous NH_(3) or NaOH to (C ) produced first a precipitate which dissolves in excess of the respective reagent to poduced a clear solution. Similarly addition of excess of potassium ferrocyanide to (C ) produced a precipitate (D) which also dissolves in aqeous NaOH giving a clear solution. Identify (A),(B),(C ) and (D ). Write the equation of the reactions involved.

A white substance (A) reacts with dilute H_(2)SO_(4) to produce a colourless suffocating gas (B) and a colourless solution (C )/ The reaction of gas (B) with potassium iodate and starch solution produce a blue colour solution. Aqueous Solution of (A) gives a white precipitate with BaCl_(2) solution which is soluble in dilute HCl . Addition of aqueous NH_(3) or NaOH to (C ) produced first a precipitate which dissolves in excess of the respective reagent to poduced a clear solution. Similarly addition of excess of potassium ferrocyanide to (C ) produced a precipitate (D) which also dissolves in aqeous NaOH giving a clear solution. Identify (A),(B),(C ) and (D ). Write the equation of the reactions involved.